Google yesterday released a dev-only build of Chrome for Mac OS, Linux and Windows which comes loaded with rough-round-the-edges versions of the Geolocation API.

The latest update comes a few days after Google pushed out a Windows-only beta of its open source Chrome browser to its users.

Google Chrome wonk Karen Grunberg wrote on the company’s blog that geolocation was switched off by default in the 5.0.342.1 build.

Testers happy to reveal their exact whereabouts to websites they visit will first need to enable the API, said Grunberg. Both Windows and all versions of Mac OS X (with the exception of Mac10.6) support Wi-Fi-based location.

She said that permissions would not be permanent, and instead a tester would be re-prompted every time. Meanwhile, the “associated UI is incomplete,” warned Grunberg.

Elsewhere in the build, Google said it had improved plugin stability in the Mac version and removed duplicate lists recently closed sites. Chrome mavens have also slotted HTML5 databases into the Mac cookie manager.

On the Chrome Frame side of things, the ad broker said it had fixed crashes and improved cookie behaviour.

Grunberg warned that known issues in the dev-only build included crashes when trying to open Gmail offline.

Google has the full rundown here, but remember the build is intended only for testers happy to play with an unstable version of the software on their machines. ®